package com.pilot.common.widget.wheelview;

import android.database.DataSetObserver;
import android.view.View;
import android.view.ViewGroup;

/**
 * Wheel items adapter interface
 *
 * @see <a href="https://code.google.com/p/android-wheel/source/browse/trunk/wheel/src/kankan/wheel/widget/adapters/WheelViewAdapter.java">
 * https://code.google.com/p/android-wheel/source/browse/trunk/wheel/src/kankan/wheel/widget/adapters/WheelViewAdapter.java </a>
 */
public interface WheelViewAdapter {

	/**
	 * Gets items count
	 *
	 * @return the count of wheel items
	 */
	int getItemsCount();

	/**
	 * Get a View that displays the data at the specified position in the data set
	 *
	 * @param index       the item index
	 * @param convertView the old view to reuse if possible
	 * @param parent      the parent that this view will eventually be attached to
	 * @return the wheel item View
	 */
	View getItem(int index, View convertView, ViewGroup parent);

	/**
	 * Get a View that displays an empty wheel item placed before the first or after the last wheel item.
	 *
	 * @param convertView the old view to reuse if possible
	 * @param parent      the parent that this view will eventually be attached to
	 * @return the empty item View
	 */
	View getEmptyItem(View convertView, ViewGroup parent);

	/**
	 * Register an observer that is called when changes happen to the data used by this adapter.
	 *
	 * @param observer the observer to be registered
	 */
	void registerDataSetObserver(DataSetObserver observer);

	/**
	 * Unregister an observer that has previously been registered
	 *
	 * @param observer the observer to be unregistered
	 */
	void unregisterDataSetObserver(DataSetObserver observer);
}
